Manufacture of abrasive articles



Patented Apr. 6, 1937 ANUFA TURE OF Norman of Delaware No Drawing.

16 Claims.

a continuation in part of 315,603 filed This application is my copending application Serial No.

s invention relates in general to an abrasive article comprising abrasive particles, silicon carbide, aluminum oxide, etcil, with resinous materials.

In the manufacture of synthetic resin bonded wheelsone method of procedure has been to mix the abrasive with tiall process, we heels containcondensation products as follows:

continuance of the reaction befor has proceeded to the point of solidification.

P. Robie, Washington, an by mesne assiimments, to The Carborundum Company, Niagara Falls, N.

Application July 11,

In C nada,

ABRASIVE ARTICLES Y., a, corporation 1931, Serial June 28, 1929 Under these condifound that the dry B stage" polymerization, obtained by using in the original mix resins in difierent stages of polymerization and curing them together.

resin resin bonding Example III.'I'he of Example I y a substantially homogeneous e B stage". Other modifications of my process than those given in. the preceding examples may be used. The following variations are possible.

for the liquid phenolic esin.

2. Other dry powdered heat hardenable resins such as those produced by the partial reaction of phenolic bodies with aldehydes or aldehyde derivatives, urea and its derivatives with aldehydes, y other synthetic resins, either singly or as mixtures of two or le types, may be substituted for the dry powdered phenolic condensation product resin.

flint, clay, such as pitch, rosin, shellac, powdered plastic waste, celr ynthetic gums may ed with the dry powdered hardenabie. resin to modify its properties as desired or may be used without the dry reactive resin.

4. Other abrasives, such as emery, garnet, flint, corundum and silicon carbide may be used.

5. The amount 0! bond may be varied. The correct proportion of liquid bonding material to m be determined for each percent oi total bond to obtain the right consistency.

My process has a number of advantages:

1. The mix as given in the example above contains no volatile solvent to be weather conditions.

2. The absence of plasticizers tends to prevent the boiling during the curing period.

3. The process does away with the extra added cost of volatile solvents and volatile plasticizers. bond promotes firm adhed abrasive. dimcult to distribute in molds,

distributed condition of the other words, the mixture can volatile solventzlatnd volatile icles from 5. Them no on account oi the coated grains. In be easily poured.

I claim:

1. In the manufacture of an abrasive article e process comprising mixing the abrasive grains with a liquid reactive resin, addke the mixture workable, forming the article under pressure,

article comprising abrasive s, a urea-condensation product bonding material adhering to the surface of the granules and a phenolic condensation product binder ad hering to said bonding material.

4. The process an abrasive article which comprises wetting abrasive grains wi h liquid phenol condensation product resin, coating rigidity the two resinous phases.

5. An abrasive article of the character obtainable by wetting abrasive grains w condensation product resin, grains with dry powdered potentially reactive phenol condensation product resin and hence 75 reducing the stickiness of iorrning the mixture under pressure into the shape of an article, and heating the formed, mixture to rigidity the two resinous phases.

6. In the manufacture of abrasive articles, the steps which comprise mixing abrasive grain with a liquid heat-hardening phenolic condensation product resin so as to wet the grain, then mixing the thus wetted grain with a dry powdered heathardening resinous partial reaction product of a phenol body and a compound 0! the group composed oi aldehydes and aldehyde derivatives 50 as to coat the wet abrasive grains with the dry powdered resin, the liquid and dry resins being so proportioned as to give a substantially dry loose abrasive mix, forming the article under pressure from such mix, and hardening the resinous bond by heating.

'7. In the manufacture of abrasive articles, the steps comprising mixing liquid reactive heat-hardening resin so as to wet the grain, thus wetted grain with a dry powdered heat-hardening reactive resin in an amount cient to coat the wet abrasive grains and form a substantially dry loose easily pourable abrasive mix, forming the article under pressure from such mix, and hardening the 8. In the manufacture of abrasive articles. the grain with a heat-hardening liquid resin so as to wet the grain, then mixing the thus wetted grain with a dry powdered heat-hardening partial reaction product resin, the liquid and dry resins being so proportioned as to give a loose readily pourable abrasive mix, iorming the article under pressure from such mix, and hardening the resinous bond 9 The method of making a synthetic a resin abrasive article which consists in coatwith a liquid synthetic resin, in then coating the thus resin coated grand at room temperatures and fusible at elevated temperatures, both coatings producing a resin bond for the abrasive granules, in so proportioning the coatings and granules as to provide a relatively loose and granular cohesion when compacted, in compacting the mass formed and rinsing and hardening the bond by heating.

10. An abrasive article consisting of uniformly distributed abrasive granules bonded together with a synthetic resin, the separate abrasive granules being coated with a film of synthetic resin bond formed of a coating or liquid added coating thetic resin.

11. In the process oi making abrasive articles, the step which comprises bonding abrasive grains with a resinous bonding material formed from a potentially reactive liquid synthetic resin and fusible solid synthetic resin.

12. In the manufacture the steps comprising mixing abrasive grains with a liquid reactive resin and a powdered solid reactive resin to make a workable mix, forming the article from the mix, nd hardening the resinous bond.

13. An abrasive article having the abrasive granules thereoi bonded with theresinous reaction product formed by the reacting and hardening of a be material containing a liquit reactive resin and a solid reactive resin.

14. In the manufacture of abrasive article:

synthetic resin and an of pulverized and fusible syncapable of I by the fusion and hardening the steps comprising mixing abrasive grain with the reaction product obtained by heating a liquid a liquid reactive resin and a dry powdered solid reactive resin and a powdered solid fusible resin. ticle comprising abrasive and heating the article. granules and a bond therefor comprising a; hard- 5 15. An abrasive article comprising abrasive ened urea condensation product. 5

grain bonded with a resinous bond comprising NORMAN P. ROBIEh 

